class_docstr: Tests for core matrix
docstr: Test that core_matrix returns the correct matrix when positions are differentiable.
docstr_tok: ["Test","that","core_matrix","returns","the","correct","matrix","when","positions","are","differentiable","."]
code: def test_core_matrix_diff_positions(
      self, symbols, geometry, alpha, c_ref
  ):
      r"""Test that core_matrix returns the correct matrix when positions are differentiable."""
      mol = qchem.Molecule(symbols, geometry, alpha=alpha)
      r_basis = mol.coordinates
      args = [mol.coordinates, mol.alpha, r_basis]
      c = qchem.core_matrix(
          mol.basis_set, mol.nuclear_charges, mol.coordinates
      )(*args)
      assert np.allclose(c, c_ref)
  
imports: import pytest
  import pennylane
  from pennylane import numpy
  from pennylane import qchem
label_desc: Use image node_id 3 for calling the TestCoreMat obj's underlying member method code with example usage: obj.test_core_matrix_diff_positions(symbols, geometry, alpha, c_ref) without return types